Question 4
- (a) Use a sketch to show the correct use of the hand file.
(b) (i) State the reason for fettling a casting.
(ii) List four defects in sand casting.
(c) Explain why mild steel cannot be hardened by heating and quenching.
Observation
The candidates performed well on the question in all but 4(b) (i). The solution of the poorly answered part of the question is as given below.
(b) (i) The reason for fettling a casting
It is done to enable the casting to be cleaned